Ethers and esters of 2-methylnaphthalene as resin plasticizers



United States Patent ()fiice 3,048,600 Patented Aug. '7, 1962 This invention relates to methylnaphthalene derivatives useful as resin plasticizers, especially for polyvinyl chloride resins.

Certain synthetic resins such as polyvinyl chloride require the addition of plasticizers to facilitate molding or other applications thereof. I have discovered certain novel derivatives of methylnaphthalene which may be produced without difliculty by a method of my invention, and will serve as well for plasticizing resins as other compounds previously employed, such as dioctyl phthalate and dioctyl sebacate. The compounds which I have discovered are lower acyloxymethylalkylnaphthalenes and alkoxymethylalkylnaphthalenes. These compounds are compatible with polyvinyl-chloride resins and upon curing, give elastomeric products with excellent strength properties. As a preliminary to the production of the methylnaphthalene derivatives I first make from methylnaphthalene a halomethylalkylnaphthalene and then convert the latter, e.g., 1-chloromethyl-2-methylnaphthalene, to an ester or ether by suitable reagents.

The novel compounds of my invention have the following general structural formula:

CHiRi where R is an alkyl group with l to 12 carbon atoms and R is an acyloxy or allcoxy group including from 1 to 18 carbon atoms. I produce the compounds by the reaction:

R G3 RlY CHzX CHzRt where X is a halogen such as chlorine, bromine or iodine and Y is hydro-gen or an alkali metal such as sodium or potassium. The preferred halogen is chlorine because of its low cost.

A complete understanding of the invention may be obtained from the following detailed explanation of the manufacture of several typical examples.

As the starting material for any of the several com pounds, a halomethylalkylnaphthalene was made'from methylnaphthalene by the following procedure:

Z-methylnaphthalene (639 grams, 4.5 moles) was dissolved in ligroin (700 grams, HP. 100 to 110 C.) and placed in a 5000 ml. flask containing650 grams of concentrated hydrochloric acid. T 0 this mixture 225 grams (7.5 moles) of paraformaldehyde was added, the mixture was agitated and heated to between 80 and 90 C. with a stream of dry hydrogen chloride being passed through. After eight hours the reaction was discontinued and the mixture permitted to cool. On separation of the layers, the organic layer was washed and distilled. The product was collected at 133 to 142 C. under 3.0 mm. Hg absolute pressure and amounted to 520 grams l-chloromethyl-2-methylnaphthalene (61% yield, MP. 62 to 64 C.).

When a mixed 1- and 2-methylnaphthalene was substituted for 2-methylnaphthalene, a liquid product boiling at 131 to 147 C. under 3.0 mm. pressure was obtained in yields up to Chloromethylmethylnaphthalenes prepared according to the above description were used for the synthesis of the novel plasticizer compounds as explained in detail herebelow;

Example 1.--2-Methylnaphthylmethyl Butyrate (MNMB) A suspension of sodium butyrate (33.0 grams, .30 mole) in 150 ml. of N,N-dimethylformamide was treated with 1-chloromet-hyl-2-methylnaphthalene (50.0 grams, .262 mole) and heated to between and C. with agitation for 10 /2 hours. The following reaction resulted.

CH G H sodium butyrate l-chloromethyl- Z-methylnaphthyl- 2-methylnaphthalene methyl butyrate The reaction mixture was filtered and distilled under vacuum. The desired Z-methylnaphthylmethyl butyrate (MNMB) distilled at 150 to 158 C. under 1.9 mm. Hg absolute pressure and the yield amounted to 55.0 grams (86% yield). The compound had a refractive index of 1.5694 at 253 C. Its composition was: C, 78.3%; H, 7.6% compared to C, 79.3 and H, 7.4, calculated for C H O Example II.--x-methylnaphthyl-(1 0r 2)- methyl pelargonate Using the procedure described in Example I, sodium pelargonate (492 grams) was treated with x-chloromethyl-(l or 2)-methylnaphthalene, giving 730 grams (82% yield) of the desired x-methylnaphthyl-(l or 2) methyl pelargonate. The product distilled at to C. under .4 mm. Hg absolute pressure and had a refractive index at 25 C. of 1.5416.

Example IH.2-m'eihylnaphthylmethyl 9,10-epoxystearate To a suspension of sodium oleate (39.0 grams, .128 mole) in 125 ml. of N,N-dimethylformamide, 28.5 grams (.150 mole) of 1-chloromethyl-2-methylnaphthalene was added and the mixture heated to between 135 and 145 C. for 8% hours with vigorous agitation. The following reaction occurred:

CH2 Cl Ca leton-armou- (CH -COONa sodium oleate l-chloromethyl- Z-methylnaphthalene ll CHzOCC 7H 3 NaCl 2-methyluaphthylmethyl oleate The reaction mixture was vacuum-distilled, giving 41.5 grams (74% yield) of Z-methylnaphthyhnethyl oleate.

'The product distilled at 257 to 260 C. under 1.5 mm. Hg absolute pressure and'had a refractive index of 1.5263 at 25.5 C. Its composition was: C, 82.2%; H, 10.2%. This compared to: C, 82.6%; H, 10.0%, calculated for 30 44 2 A solution of peracetic acid (9.5 grams, .125 mole) and sodium acetate (1.4 grams) in 14.1 grams of acetic acid was added dropwise to 50.0 grams (.114 mole) of Z-methylnaphthylmethyl oleate at 35 C. The following reaction occurred:

2-methylnaphthylmethyl oleate peracetlc acid Z-methylnaphthylmethyl 9, IO-epoxystearate my 0 01 l.l-chloromethyl-Z-methylnaphthalene 1- (2-oxapentenyl-4) -2 math ylnaphthalene The product, 1-(2-oxapentenyl-4 )--2methylnaphthalene,

4 and amounted to 47.1 grams (72% yield). Its composition was: C, H, 7.6%. This compared to: C, 85.2%; H, 7.6% calculated for C H O.

Example V.-1-(2-0xadodecyl) -2-methylnaphthalene (ODOMN) ml. of l-decanol and 16.2 grams (.30 mole) of sodium methoxide were placed in a 500 ml. flask. The mixture was heated to 150 C. for two hours, and all of the methanol formed was removed. The solution was treated with 55 grams (.29 mole) of l-chloromethyl- .Z-methylnaphthalene, heated for one hour at to C., cooled andfiltered. The following reaction occurred:

O HBONa CH -(CH2)-CH;OH CH3'(CHI)8-GH7ON3 l-decanol 1- chloromethyl-zmet hylnaphthalene CH;-O--GHr-- (CH1)s-CH 1- (2-oxadodecyl) -2-meth ylnaphthalene Distillation of the filtrate produced 61.1 grams (67.1%) of 1-(2-oxadodecyl)-2-methylnaphthalene boiling :at 195 to 205 C. under 2.0 mm. Hg absolute pressure andhaving a refractive index of 1.53.24 at 285 C. The product analyzed: C, 84.4%; H, 10.2% compared to C, 84.5%; H, 10.2%, calculated for C H O.

Example VI .1 -(2-0xa-4-ethyl0clyl -2-methy lnaphthalene (OEOMN) Employing the identical procedure used in the prepara tion of 1-.(2-oxadodecyl)-2-methylnaphthalene, 1-(2-oxa- 4-ethyloctyl)-2-methylnaphthalene was obtained in a yield of 57%. The compound distilled at to C. under 3.0 mm. Hg absolute pressure and had a refractive index of 1.5458 at 19.7 C. It analyzed: C, 84.2%; H, 10%,compared to C, 83.9%; H, 10.5%, calculated for C20H300- Example V1I.1 (2,5,8-Trioxad0decyl)-2 Methylnaphthalene (TODMN) Sodium hydroxide (13.2 grams, 0.32 mole) was dissolved in 130 grams of diethylene glycol monobutyl ether, and the solution was treated with 60 grams (.31 mole) of '1-chloromethyl 2-methylnaphthalene. The mixture was kept at 120C. for 4 hours, cooled and filtered. The following reactionoccurred:

'dlethylene glycol monobutyl'ether distilled at 113 to 114 C. under .7 mm. Hg absolute pressure, had a refractive index of 1.5918 at 24.6 C.,

(not isolated l-chlorome'thyl 2- -methylnaphtha'lene 1- (2,5,8-trioxadodecy1) -2-methylnaphthalene Distillation of the filtrate yielded 77 grams (77% yield.) of 1 (2,5,8-trioxadodecyl) -2-methylnaphthalene. The

compound distilled at 191 to 198 C. under 1.5 mm. Hg absolute pressure and had a refractive index of 1.5422 at 25 C. It analyzed: C, 75.8%; H, 8.7%. This compared to C, 75.9%; H, 8.9%, calculated for C H O Example VIII .1 -(2,5 -Di0xan0nyl) -2-M ethylnaphthalene 10.6 grams (0.27 mole) of sodium hydroxide and 82 grams of ethylene glycol monobutyl ether were placed in a 500 ml flask and the mixture heated and stirred until the sodium hydroxide dissolved. The solution was treated with 50 grams (0.27 mole) of l-chloromethyl-Z-methylnaphthalene in 300 ml. of ethylene glycol monobutyl ether, refluxed for 8 hours, cooled and filtered. The reaction was:

Upon vacuum distillation, the filtrate yielded 54.6 grams (75% yield) of 1-(2,5-dioxanonyl)-2-methylnaphthalene. The product distilled at 149 to 155 C. under 1.0 mm. Hg absolute pressure and had a refractive index of 1.5509 at 25 C. It analyzed: C, 79.5%; H, 8.9%, compared to C, 79.4%; H, 8.9%, calculated for C H O Example IX .1 (7 -Acetoxy-2,5 -Di0xah eptyl -2-M ethy lnaphthalene 12.6 grams (.315 mole) of sodium hydroxide was dissolved in 120 grams of diethylene glycol. This solution was heated to 140 C. and treated with 1-chloromethyl-2- methylnaphthalene (60.0 grams, .314 mole). The resulting mixture was heated for 4 hours and filtered. The

reaction was:

NaOH HO-(CH;) O-(CH2)2-OH HO(OH1)gO(CH 0Na diethylene glycol (not isolated) 1-eh1oromethyl-2- methylnaphthalene CHg-O-(CHz)z-O(CH2)TOH \JCH:

6 C. Its composition was: C, 72.2%; H, 7.7%, compared to C, 71.6%; H, 7.3%, calculated for C H O The methylnaphthalene derivatives produced as explained above may be used as plasticizers by incorporating them in resins such as polyvinyl chloride and polyvinyl chloride-acetate, in amounts from 10 to 120 parts per parts of resin by weight. About 40 parts plasticizer per 100 parts resin by weight appears to give the best results.

The results of tests of resins plasticized with my compounds indicate that the latter give elastomers which are superior in strength and have less plasticizer migration than dioctyl phthalate. At low cure temperatures, e.g., 300 F., the elastomers produced with my novel plasticizers are significantly superior in tensile strength, tear resistance and elongation. Low cure temperatures are, of course, very desirable in many applications.

It will be evident that the plasticizers of my invention may be readily produced from inexpensive starting materials and thus materially supplement the compounds now being used as resin plasticizers.

Although I have disclosed herein the preferred practice of my invention, I intend to cover as well any change or modification therein which may be made without departing from the spirit and scope of the invention.

I claim:

1. The compound 2-methylnaphthylmethyl-9,10-epoxystearate.

2. The compound 1- (2,5,8-trioxadodecyl)-2-methylnaphthalene.

3. The compound 1-(2,5-dioxanonyl)-2-methylnaphthalene.

4. The compound 1- (7-acetoxy-2,5-dioxaheptyl)-2- methylnaphthalene.

References Cited in the file of this patent UNITED STATES PATENTS 2,411,428 Hechenbleikner Nov. 19, 1946 2,459,526 Hechenbleikner I an. 18, 1949 2,591,604 Reck Apr. 1, 1952 2,722,555 Amidon Nov. 1, 1955 2,799,699 Smith July 16, 1957 2,891,922 Johnson June 23, 1959 2,898,319 Petropoulos Aug. 4, 1959 2,925,426 Schroeder Feb. 16, 1960 FOREIGN PATENTS 516,280 Germany Jan. 21, 1931 810,199 Germany Aug. 6, 1951 OTHER REFERENCES Hackhs Chemical Dictionary, 2nd ed., page 21 (1937). Balfe et al.: Journ. Chem. Soc., pages 797803 (1946). Arnold et al.; J.A.C.S., vol. 69, page 2324 (1947). Kruyt et -al.: Chem. Abs., vol. 45, page 7287 (1951). Lapkin et al.: Chem. Abs., vol. 45, page 7081 (1951). Edwards: I. Agr. South Australia, vol. 56, pages 131-2 (October 1952).

Chakravarti et al.: Journal Indian Chemical Society, vol. 30, pages 750-4 (1953).

Patent No. 3,048,600 August. 7 1962 John J. Jaruzelski in the above numbered petthat error appears ent should read as It is hereby certified d that the said Letters Pat ent requiring correction an corrected below.

the top of the benzene line 21, the legend at tead of as in the patent:

Column 4,

own below ins ring should appear as sh CH 0CH ((3H -CH e beginning of the reaction line l6 the legend at th as in the patent:

column 5,

hown below instead of should appear as s C H -O(CH OH Signed and sealed this 13th day of November 1962.

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Commissioner of Patents Attesting Officer 

1. THE COMPOUND 2-METHYLNAPHTHYLNETHYL-9,10-EPOXYSTRARATE.
 3. THE COMPOUND 1-(,5-DIOXANONYL)-2-MTHYLNAPHTHALENE.
 4. THE COMPOUND 1- (7-ACETOXY-2,5-DIOXAHEPTYL)-2METHYLNAPHTHALENE. 